While the SNECMA machine may have been the first of this type of
aircraft to actually be constructed, the approach itself was first
put forward in Germany late in World War II as a possible layout
for point defense interceptors at a time when German airfields were
under regular attack by Allied bombing. Two proposed Heinkel designs, the Wespe and
the Lerche II were to use this layout, but
neither of them was ever actually built.

SNECMA's experiences demonstrated formidable control problems,
both with balancing the aircraft during vertical flight, and in
transitioning between vertical and horizontal flight and back.

An American design, the Hiller VXT-8, was abandoned before a
prototype was ever built.